Existing covers for devices with touch sensors such as smart phones and tablets are available in a wide variety. The covers or cases are usually removable, and devices can be configured to enter a “lock mode” when a cover is applied (closed). Some covers do not cover the touch sensor of the device, and some are transparent to light. So-called smart covers can be used to provide limited interactivity with devices when they are attached. A cover can be electrically connected to the device and have a processor of its own.
The embodiments described below are not limited to implementations which solve any or all of the disadvantages of known devices and covers.